Book reviews

Biersack, H. J.; Valkema, R.

doi:10.1007/bf00181074

Cited by 22 publications

(30 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The free flight paths are chosen with an exponential probability density [34] and a mean value determined by the target density and p max [35]. In IMSIL, the maximum impact parameter p max and consequently the mean free flight paths are taken to depend on the energy in such a way that all nuclear energy transfers down to a specified threshold are considered [36].…”

Section: Monte Carlo Simulation Modelmentioning

confidence: 99%

“…In IM-SIL the ions start at a distance p max outside the target such that their undeflected direction of motion goes through the origin. Positions of potential collision partners are determined in the usual way, but target atoms are generated at these positions only if they are inside the user-defined surface [35]. Such an algorithm is most likely not applied in SRIM which might account for its failure to correctly predict glancing angle sputter yields [37].…”

Section: Monte Carlo Simulation Modelmentioning

confidence: 99%

See 1 more Smart Citation

Probing the limitations of Sigmund's model of spatially resolved sputtering using Monte Carlo simulations

2016

View full text Add to dashboard Cite

Sigmund's model of spatially resolved sputtering is the underpinning of many models of nanoscale pattern formation induced by ion bombardment. It is based on three assumptions: (i) the number of sputtered atoms is proportional to the nuclear energy deposition (NED) near the surface, (ii) the NED distribution is independent of the orientation and shape of the solid surface and is identical to the one in an infinite medium, and (iii) the NED distribution in an infinite medium can be approximated by a Gaussian. We test the validity of these assumptions using Monte Carlo simulations of He, Ar, and Xe impacts on Si at energies of 2, 20, and 200 keV with incidence angles from perpendicular to grazing. We find that for the more commonly-employed beam parameters (Ar and Xe ions at 2 and 20 keV and non-grazing incidence), the Sigmund model's predictions are within a factor of 2 of the Monte Carlo results for the total sputter yield and the first two moments of the spatially resolved sputter yield. This is partly due to a compensation of errors introduced by assumptions (i) and (ii). The Sigmund model, however, does not describe the skewness of the spatially resolved sputter yield, which is almost always significant. The approximation is much poorer for He ions and/or high energies (200 keV). All three of Sigmund's assumptions break down at grazing incidence angles. In all cases, we discuss the origin of the deviations from Sigmund's model.

show abstract

Section: Monte Carlo Simulation Modelmentioning

confidence: 99%

Section: Monte Carlo Simulation Modelmentioning

confidence: 99%

Probing the limitations of Sigmund's model of spatially resolved sputtering using Monte Carlo simulations

2016

View full text Add to dashboard Cite

show abstract

“…16,17 This method supposes that the majority of the ion induced alteration is due to ballistic mixing ͑which assumption is satisfied for this case, since the other important distorting process the surface roughening results in less than 1 nm rms roughness using the earlier sputtering parameters͒, 18 which is properly described by TRIM simulation. 17,19 The method also considers the intrinsic interface roughness or waviness by a Gaussian broadening. Figure 2 shows one period of the measured depth profiles for the as received and annealed specimens, respectively.…”

mentioning

confidence: 99%

Interdiffusion in amorphous Si/Ge multilayers by Auger depth profiling technique

Csík

Langer

Beke

et al. 2001

Journal of Applied Physics

View full text Add to dashboard Cite

It has been shown by the Auger depth profiling technique that the concentration profile at the initially sharp Si/Ge interface in amorphous Si/Ge multilayers shifted but remained still sharp after a heat treatment at 680 K for 100 h. At the same time the fast diffusion of Si resulted in the formation of an almost homogeneous Ge͑Si͒ amorphous solid solution, while there was practically no diffusion of Ge into the Si layer. This is direct evidence on the strong concentration dependence of the interdiffusion coefficient in amorphous Si/Ge system, and it is in accordance with the previous indirect result obtained from the measurements of the decay of the small angle Bragg peaks, as well as with finite difference simulations. © 2001 American Institute of Physics. ͓DOI: 10.1063/1.1331330͔Changes in atomic structures of amorphous semiconductors and their relationships to physical properties are currently of interest due to their useful optical and electronic features.1,2 Since most structural changes are related to atomic diffusion, any real understanding of the structural transformation, homogenization, etc., must be based on the knowledge of the diffusion processes. The study of diffusion in amorphous materials includes some difficulties. One of the main problems is related to the thermal stability of the amorphous phase; the diffusional measurements should be carried out at low temperatures for very short diffusion times in order to avoid structural changes due, e.g., to structural relaxation. Additionally, in amorphous semiconductors the mechanism of diffusion is also not fully understood.3-5 Thus, for example factors controlling the details of diffusional homogenization in amorphous Si/Ge multilayers are still under discussion. First of all the diffusional asymmetry ͑manifested in the strong concentration dependence of the interdiffusion coefficients͒, 6 the significant pore formation during the diffusional mixing, 7 and the possible role of diffusional stresses 8 are the most important factors indicating the need of a better understanding of the previous process.In this article interdiffusion in amorphous Si-Ge multilayered specimens is studied by Auger depth profiling. The primary objective of the present investigation is to observe the predicted asymmetric change of composition caused by the strong concentration dependence of the diffusion coefficients. Experimental results, obtained from small angle x-ray diffraction ͑SAXRD͒ measurements at different average compositions indicated a strong concentration dependence of the chemical diffusion parameters.9,10 Although such a strong concentration dependence inevitably should lead to a significant curvature on the ln(I/I 0 ) ͑I/I 0 is the normalized height of the first order SAXRD peak͒ versus time plots 11 ͑and to oscillatory behavior of the higher order peaks͒, later on the experimentally observed curvature was rather attributed by the same group to the effects of structural relaxation and coupling back effects of stresses of diffusional origin were also excluded....

show abstract

“…Ge negative-ion beam at a diameter of 8 mm was implanted in 50-nm SiO2 three times at different energies of 50, 20 and 10 keV to make a plateau of Ge concentration in depth direction of the layer. Fig.2 shows various depth profiles of Ge atoms calculated by TRIM-DYN [8], where the profile has a plateau at Ge 3 at.% from 15 to 42 nm in depth.…”

Section: Experimental 21 Very Thin Sio2 Layer and Ge Negative-ion Immentioning

confidence: 99%

Evaluation of Ge Oxidation State in Ge Nanoparticles Formed in Thin SiO<sub>2</sub> Layer by Negative-Ion Implantation and Successive Two-Stage Annealing

Tsuji

Kato

Mayama

et al. 2016

Trans. Mat. Res. Soc. Japan

View full text Add to dashboard Cite

Low-voltage electroluminescence (EL) at 390 nm was obtained in a MIS structure at applied voltage of 15-30 V from 3 at.% Ge-implanted 50-nm SiO2 layer samples after the successive two-stage annealing. From the optical emission, Ge-related oxygen deficiency centers (Ge-ODCs) are speculated to exist at a shallow depth. To clarify the creation depth of Ge-ODCs and roles of nanoparticles (NPs), Ge-oxidation states in the SiO2 layer and Ge NP were measured by two methods, i.e., X-ray photoelectron spectrometry (XPS) and 3-dimensional atom probe (3D-AP) after annealing: (1) in nitrogen gas flow at 700 o C for 1h and (2) in air flow at 700 o C for 1h. In XPS with Ar-etching, a significant increase of Ge-O bonds was shown at 15 -30 nm in depth. Ge-Ge bonds decreased in the whole depth region. In 3D-AP, relatively large four Ge NPs were detected in the Ge-implanted SiO2 layer. The shallowest NP was spherical with at diameter of 5 nm and had a Ge-core at 2 nm in diameter and Ge-oxide shell of with 1 -2 in thickness. So Ge-O bonds were surely created between core and shell. The role of Ge NP is to ensure forming G-ODCs in NP and interrupting progress of Ge oxidation to the deeper side.

show abstract

Book reviews

Cited by 22 publications

References 0 publications

Probing the limitations of Sigmund's model of spatially resolved sputtering using Monte Carlo simulations

Probing the limitations of Sigmund's model of spatially resolved sputtering using Monte Carlo simulations

Interdiffusion in amorphous Si/Ge multilayers by Auger depth profiling technique

Evaluation of Ge Oxidation State in Ge Nanoparticles Formed in Thin SiO<sub>2</sub> Layer by Negative-Ion Implantation and Successive Two-Stage Annealing

Contact Info

Product

Resources

About